Question

Circinotropous ovule occurs in

• A. Cicer
• B. Opuntia
• C. Ranunculus
• D. Polygonum

Answer 1

The correct option is B

Opuntia

The correct option is B.

Explanation of the correct option:

1. The length of the funiculus increases in a cinotrocirpous ovule, eventually covering the whole ovule.
2. In seed plants, the ovule is a component of the female reproductive organ.
3. The nucellus, the integuments that make up the outermost layer, and the female gametophyte are all part of it.
4. The ovule of Opuntia is Circinotropous.
5. The length of the funiculus grows longer and covers the entire ovule in this form of ovule.

Explanation of the incorrect options:

Option A:

1. Cicer has an anatropous ovule, meaning the ovule's body is rotated 180 degrees and the micropyle is close to the funiculus.
2. The micropyle and the chalaza are in a straight line, whereas the hilum is at a 90° angle to the micropyle.

Option C:

1. Ranunculus has a hemi anatropous ovule, which means the ovule's body is twisted 90 degrees.
2. The micropyle and chalaza are in a straight line, but the funiculus is at a 90-degree angle to both of them.

Option D:

1. The ovule of Polygonum is orthotropous.
2. The micropyle, chalaza, and funiculus are all in a straight line in this form of ovule.

Final answer: Circinotropous ovule occurs in Opuntia.